Primary Standards:
MAFS.K.OA.1.a Use addition and subtraction within 10 to solve word problems involving both addends unknown, e.g., by using objects, drawings, and equations with symbols for the unknown numbers to represent the problem.
MAFS.K.OA.1.5 Fluently add and subtract within 5. *(By the end of kindergarten, students should know addition and subtraction facts with totals to 5. They also demonstrate an understanding of what it means to add and subtract. Successful students should have a variety of experiences, using concrete models and drawings to show these combinations.)
Connecting Standards:
MAFS.K.OA.1.1 Represent addition and subtraction with objects, fingers, mental images, drawings, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
MAFS.K.OA.1.2 Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.
Content Knowledge:
In put together/take apart situations, two quantities jointly compose a third quantity (the total), or a quantity can be decomposed into two quantities (the addends.) These situations are acted out with objects initially, then students move to conceptual mental understanding of seeing the addends and seeing the total, for example, seeing both 3 red apples and 5 green apples, but still seeing there are 8 total apples.
Separating or take apart – both addends unknown situations play an important role in kindergarten because they allow students to explore various compositions of each number (1-10.) This will help students to build more advanced strategies based on number sense to solve problem types.
Equations used in this Unit should show the operation symbol on both sides of the equal sign (5 = 2 + 3, 2 + 3 = 5) and include symbols for the missing addends (5 = ? + ?, ? + ? = 5.) Matching equations helps our students understand the meaning of the equal sign as same as, and know equations can be written in different ways.
GCG 1 – Learning Goal: As a Mathematician, I will be able to Represent and Solve Put Together/Take Apart – Both Addends Unknown (Sums within 5)
- Step 1: Students can use concrete materials to model put together/take apart-both addends unknown problems and provide verbal explanations of solutions for sums within 5
- Step 2: Students can use concrete materials and/or drawings to solve put together/take apart-both addends unknown problems and provide verbal explanations of solutions for sums within 5
- Step 3: Students can match their model and/or drawings of put together/take apart-both addends unknown problems with a given equation or expression and provide a verbal explanation as to why they match for sums within 5
GCG 2 – Learning Goal: As a Mathematician, I will be able to Represent and Solve Put Together/Take Apart – Both Addends Unknown (sums to 10)
- Step 1: Students can use concrete materials to model put together/take apart-both addends unknown problems and provide verbal explanations of solutions (sums within 10)
- Step 2: Students can use concrete materials and/or drawings to solve put together/take apart-both addends unknown problems and provide verbal explanations of solutions (sums within 10)
- Step 3: Students can match their model and/or drawings of put together/take apart-both addends unknown problems with a given equation or expression and provide a verbal explanation as to why they match (sums within 10)
- Step 4: Students use what they know about making a ten to solve put together/ Take apart – both addends unknown problems